My application just got approved, hence I'm posting here again although I did send the same query thru "contact".

I do about 3 century rides per year. In total I did about 10. My av timing is 28km/hr. Not very fast. Other than that its a bit of serious recreational ride over the weekends. And I love climbs.

I'm 59 yrs and weigh 59 kg, male.

Currently I'm riding a Campy Eurus low profile wheel, something like 24/28. I intend to do an upgrade and hopefully improve on my century ride timing.

I'm think of 60/60.

Will 30/60 or 60/90 benefit me better? aero wheels?

Thanks for writing. The 60/60 is a great wheel set for a road bike. In fact, it's what I ride on my road bike most of the time. Swapping to a front 30 would improve your ability to control the bike in cross winds. The increased depth of the front 60 will make handling a little more challenging, but we've found that all but the most timid athletes can confidently control the front 60. The rear 90 will give you an additional aero benefit, with a slight weight penalty. Remember though that aero will trump weight on the courses you are riding. A lot of road riders like a matching depth front and rear so the choice is really up to you. It's hard to make a bad decision.

Aero wheels will certainly help improve your times. It's hard for me to give an exact speed difference because a ride has so many variables to consider. The terrain, wind, pack dynamics etc. Your average speed could be greater than 28km/hr on some rides BUT even if your average speed is still 28km/hr, you'll have to keep in mind that it would have been slower without the aero wheels. It's a bit of a moving number.